/*
 * Copyright 2007 Rob Nielsen
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * 	http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.googlecode.proxymatic.core.handlers.method;

import com.googlecode.proxymatic.core.MethodInvoker;
import com.googlecode.proxymatic.core.ReturnTypeModifier;
import com.googlecode.proxymatic.core.RuntimeContext;
import com.googlecode.proxymatic.core.util.ReflectUtil;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class PassthroughMethodInvoker implements MethodInvoker {
    private final Method targetMethod;
    private final ParameterModifier parameterModifier;
    private final int implementationIndex;
    private final ReturnTypeModifier returnModifier;

    public PassthroughMethodInvoker(Method targetMethod, int implementationIndex) {
        this(targetMethod, ParameterModifier.NO_MODIFICATIONS, ReturnTypeModifier.NO_MODIFICATIONS, implementationIndex);
    }

    public PassthroughMethodInvoker(Method targetMethod, ParameterModifier parameterModifier, ReturnTypeModifier returnModifier) {
        this(targetMethod, parameterModifier, returnModifier, 0);
    }

    public PassthroughMethodInvoker(Method targetMethod, ParameterModifier parameterModifier, ReturnTypeModifier returnModifier, int implementationIndex) {
        this.targetMethod = targetMethod;
        this.parameterModifier = parameterModifier;
        this.returnModifier = returnModifier;
        this.implementationIndex = implementationIndex;
    }

    public Object invoke(Method method, Object[] parameters, RuntimeContext context) throws Throwable {
        try {
            targetMethod.setAccessible(true);
            Object[] modifiedParameters = parameterModifier.modifyParameters(parameters, method.getParameterTypes(), targetMethod.getParameterTypes());
            Object targetObject = ReflectUtil.isStatic(targetMethod) ? null : context.getImplementationObject(implementationIndex);
            Object result = targetMethod.invoke(targetObject, modifiedParameters);
            return returnModifier.modifyReturnType(method, result, targetMethod.getReturnType());
        } catch (InvocationTargetException e) {
            throw e.getTargetException();
        }
    }

    public Class[] getExceptionTypes() {
        return targetMethod.getExceptionTypes();
    }
}
